- Residents terrified as alleged chlorine attack on market followed by airstrikes
- Use of chemical weapons in Syria becoming "new normal," doctors' group says
This story contains graphic images, including some of child victims.
(CNN)Fresh airstrikes rained down Wednesday on a rebel-held neighborhood in Syria's east Aleppo, killing two people at a market where an alleged chlorine gas attack injured more than 100 people a day earlier, an activist told CNN.
Children injured in alleged chlorine attack
The drop was followed by four rockets fired by military jets, he said.
Medical sources point to regime
Expert sees resurgence in chemical weapons
Chlorine, element 17 on the periodic table, is a so-called dual-use chemical with a number of industrial uses.
Fatal in high concentrations and harmful in lower doses, chlorine gas can also be used as a crude weapon. The chemical was widely used in the First World War.
When inhaled, it reacts with water in the body to produce corrosive hydrochloric acid that damages human cells.
The effects can begin within seconds to minutes, causing victims to experience difficulty breathing, chest tightness, coughing and eye and skin irritation. Inhaling high levels of chlorine can cause pulmonary edema -- when fluid builds up in the lungs.
In conflict situations, delivery methods include dropping chlorine gas onto civilian areas from aircraft via improvised barrel bombs.